Can't add an image when uploading my mod to steam

[Jeffrey Vest]

I am stuck on the silliest thing. I can't add an image to my mod in the steam workshop uploader. I was uploading them before, and seeing how awful my screenshots looked. I then realized I can't change it in Steam once it's there (so frustrating). So I wanted to re-do the whole thing but now the image just won't attach. I can select it in the workshop uploader, but it just does nothing. The box stays black and nothing gets uploaded to Steam. Then on Steam all I can do is add a new image, which make the current "image" which is a dumb lack of an image, show off to the side. Help!

 

[Jeffrey Vest]

FYI this turned out to be because it doesn't take files over 1 MB. I noticed I could "randomly" attach some and not others and found the pattern.